I have the problem that when I type "startx" on the shell, it tries to start, but the screen onyl turns black. I installed the official NVIDIA driver set, it compiled the kernel module and finished sucessfully the installation. After installing , I edited the XF86Config like the driver readme said and made a reboot. I typed "startx" and the NVIDIA logo was seen for a second, then KDE began to start normally, I tried this three times, everytime with sucess. I didn't change anything and simply made another reboot, since this it the GUI doesn't want to start anymore... if I turn back to the "vesa" or "nv" generic drivers in XF86Config, it does start normally. When I reinatll the driver it sometimes works for 2 or 3 times, then it fails again.